If CONFIG_DOWNLOAD_FOLDER is set to for example "~/dl", the download
script fails to create the .hash and .dl files with the following
errors:
Cannot create file ~/dl/dropbear-2017.75.tar.bz2.dl: No such file or directory
sh: 1: cannot create ~/dl/dropbear-2017.75.tar.bz2.hash: Directory nonexistent

If the tarball already exists in the ~/dl dir, it's properly found and
used, so this issue only affects the download.pl script.
This patch calls glob() on the target dir parameter, which will expand `~`.

Fix SIGSEGV in rfc1035.c answer_request() line 1228 where memset()
is called with header & limit pointing at the same address and thus
tries to clear memory from before the buffer begins.

answer_request() is called with an invalid edns packet size provided by
the client. Ensure the udp_size provided by the client is bounded by
512 and configured maximum as per RFC 6891 6.2.3 "Values lower than 512
MUST be treated as equal to 512"

Backing up the current firmware from U-Boot over serial can take hours.
Booting a working Linux image for backup purposes is not always an option.
Using the tftpput command in U-Boot is the fastest and easiest way.

tftpput will upload the contents of a memory region to the TFTP server.
The IP address of the server is stored in the serverip variable.

Firmware installation:
- VoCore2-Lite ships with firmware forked from OpenWrt.
- Installation from the bootloader is recommended.
- If using luci/sysupgrade use the -n option (do not keep settings)
original firmware uses a modified proprietary MediaTek wireless driver.
- The wireless is disabled by default in LEDE.
- If reverting to factory firmware using the bootloader is recommended.

While debugging an issue with a client device, wpa_supplicant did not
seem to log anything at all. Make wpa_supplicant log to syslog instead
of stdout, to make debugging easier and to be consistent with hostapd.

The esi call was added to workaround a race condition between applying
a configured mac address to the wan interface and starting the protocol
(handler) as it was observed in a DHCP over ATM bridge configuration.

Martin Schiller, TDT GmbH was so kind to test with their local
infrastructure if the race condition still exists. The provided package
dumps captured behind the DSLAM shows that it doesn't. It was most
likely fixed with adding carrier support to the lantiq ptm/atm driver.

This patch cleans up the WN3000RPv3 and EX2700 setup, bringing it in line
with other similar devices:

The power led is a bicolor one. The bootloader brings the red side on at
powerup.

Instead of blinking the red side in diag.sh and need to forcefully turn it off
in 01_leds, this patch simplifies the setup by relying on the default off state
of the gpio-led driver for the red side and blinking the green side as with
other devices.